The present disclosure relates to a wireless communication signal detector, and more particularly, to a detector capable of universally detecting all broadcasting services including an orthogonal frequency division multiplexing (OFDM) scheme.
An orthogonal frequency division multiplexing (OFDM) scheme, which has been used as a useful scheme for high-speed data transmission in a wired/wireless channel, is a data transmission scheme using a plurality of carriers in which serially input data are converted in parallel, the respective converted data are modulated with a plurality of mutually orthogonal sub-carriers, that is, a plurality of mutually orthogonal sub-channels, and they are then transmitted.
The OFDM scheme is now widely being applied to such digital transmission technology as digital audio broadcasting (DAB), digital television (DTV), wireless local area network (WLAN), wireless asynchronous transfer mode (WATM), broadband wireless access (BWA), and so forth. The OFDM scheme, which was not widely used due to its hardware complexity, can now be implemented owing to the recent development of various digital signal processing technologies including fast Fourier transform (FFT) and inverse fast Fourier transform (IFFT). The OFDM scheme, being similar to a conventional frequency division multiplexing (FDM) scheme, is characterized by transmitting a plurality of sub-carriers while maintaining orthogonality therebetween, thereby obtaining the optimal transmission efficiency during high-speed data transmission. In addition, the OFDM scheme has high frequency efficiency and is robust against multipath fading. Moreover, the OFDM scheme is robust against frequency selective fading by using a superimposed frequency spectrum, can reduce the effects of inter-symbol interference with the use of a guard interval, can enable simple hardware design of an equalizer, and is robust against impulse noises.
At present, as mentioned above, the field of communication systems using the OFDM scheme is being developed variously. However, since the communication systems provide services by employing detectors or receivers suitable for their respective characteristics, corresponding detectors are required for reception of various OFDM signal services. Accordingly, there is a need for a universal blind mode detector capable of universally receiving all signal services using the OFDM scheme.
For non-OFDM communication systems which use satellite-digital multimedia broadcasting (S-DMB) and direct sequence-ultra wideband (DS-UWB) instead of the OFDM scheme, there is an attempt for unification based on a feature that they use Viterbi (VIT) or Reed Solomon decoders (RSDs) which are also used in OFDM systems.